Retrieval of Cirrus Radiative and Spatial Properties Using Independent Satellite Data Analysis Techniques

Abstract : Cirrus is one of the most poorly quantified clouds. As a part of International Satellite Cloud Climatology Project (ISCCP), intensive observations of cirrus clouds were taken in the autumn of 1986 over Wisconsin. During this First ISCCP Regional Experiment Cirrus Intensive Field Observation (FIRE Cirrus IFO), coordinated measurements from satellite, aircraft, and ground-based platforms were made of cirrus clouds. This paper deals with the verification of cirrus cloud information, both spatial and radiative, obtained for a 1986 FIRE cloud scene using measurements from two independent sensors onboard the NOAA-9 polar orbiting satellite. In addition to the wide variability in properties common for other types of clouds, cirrus clouds have the added complexity of transmissivity t values that span the entire possible domain 0 = 1. Thus, uncertainties exist in thin cirrus cloud amount, altitude, thickness, and optical properties as retrieved from satellite because the measured cirrus signal is affected additionally by an unknown radiation component from below.